As more and more electronic data becomes available for use, more and more data is saved in various information apparatuses such as individually owned personal computers, with an increasing need for an efficient information providing method.
Meanwhile, widespread use of computer networks leads to the introduction of information providing means for use on computer networks. As the information providing means, various information providing systems for collecting, accumulating, and sharing information, such as an electronic bulletin board, groupware, and a file management system, are proposed.
A conventional typical information providing system receives the registration of data, such as knowledge information or document information, for sharing information to allow registered data to be made public to users who request the information (hereinafter termed requesters).
Although such an information providing system is efficient for publicizing and sharing information, providing necessary data requires users (for example, individuals) who provide information to the information providing system to create and register data that is made public.
However, it is not easy in practice to anticipate what individually-owned knowledge and know how the other users will need and to create in advance data, which will be made public. In addition, without motivations or financial incentives, users are not willing to create data for publication and register the created data even if they have knowledge and information. That is, such an information providing system requires an information providing user to create necessary data and to register, add, change, or delete data. An information providing user finds those operations cumbersome and feels reluctant to do so.
In general, data is managed in such an information providing system by set access rights to data to maintain information security.
It is therefore necessary to determine in advance which data is to be made public to which user and to appropriately set up access rights and security management.
However, classifying a large amount of data between data to be made public and data not to be made public in advance for future information requests and use puts a heavy load on an information providing user.
Data is dealt with in various units. For example, in case of a data unit being an information unit such as an electronic file, if there are a large number of files, classifying all files between those allowed to be made public and those not allowed to be made public requires considerable costs. To allow only a part of a file to be made public, the more detailed setting and management of files are required and the operation becomes still more cumbersome.
Even if data is registered with above-described problems existing, it is difficult to provide appropriate information efficiently from the registered data to a requester while maintaining security.
An information providing system designed for information retrieval, described, for example, in Patent Document 1, is known as a system for efficiently using accumulated data while maintaining the security of it. This conventional information providing system comprises receiving means for receiving a query request that includes a query condition issued from a requester; a database that stores plural items of data; detection means for detecting data, corresponding to a query condition, from the database according to a query request; and output means for outputting exsistence information on the corresponding data in the database, as well as personal information on a person who has a predetermined right, to a requester who has made a request for, but has no access right to, the corresponding data. This conventional information processing system operates as follows.
First, the receiving means receives a query request sent from the terminal device of the requester and including a query condition.
The detection means detects data, corresponding to the query condition specified by the received query request, from the database.
Next, the output means references the access right for the detected data and, if the requester who has sent the query request has the access right, outputs the detected data to the terminal device of the requester who has sent the query request. If the requester who has sent the query request has no access right, the output means outputs information on the location of the detected data, as well as information on a person who has the access right to the information, to the terminal device of the requester who has sent the query request.
Patent Document 2 discloses the configuration of an information providing system that comprises means that is used by a special person in charge of engineering for performing an operation to confirm a query accepted from the requester's PC via electronic mail, an operation to access a private database, in which technical information not accessible to the requester is stored, for detecting technical information, an operation to create an answer based on the detected technical information, and an operation to send the answer to the requester's PC via electronic mail. This information providing system also accumulates answer log when the answer is sent.    Patent Document 1: Japanese Patent Publication Kokai JP-A No. 2005-208901    Patent Document 2: Japanese Patent Publication Kokai JP-A No. 2001-312502    Patent Document 3: Japanese Patent Publication Kokai JP-A No. 2002-132812